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HOW TO USE THE MICROSCOPE 



thus named after the mythical giant. The body is 

 pear-shaped, having a flattened head and a tapering 

 tail. There are two pairs of antermse, and five pairs 

 of short legs, by means of which the httle crustacean 

 jerks itself through the water. The females greatly 

 exceed the males in number, and are easily known 



Fig. 21. — Amceba Proteus. 

 CV, contractile vacuole ; N, nucleus. 



by the egg bags which hang on either side of the 

 lower part of the body. 



Other kinds of minute crustaceans live in fresh 

 water, but we must pass them over in order to give 

 a few other life-forms brief notice. Among them 

 we must include the Amoeba, the simplest organism 

 of which we have any knowledge. This creature is 

 plentiful among mud and decaying vegetation found 

 in ponds. It is exceedingly small, seldom reaching 



